drm/radeon: Drop legacy MST support

Right now, radeon is technically the only non-atomic driver still making
use of the MST helpers - and thus the final user of all of the legacy MST
helpers. Originally I was going to look into seeing if we could move legacy
MST into the radeon driver itself, however:

* SI and CIK both can use amdgpu, which still supports MST
* It currently doesn't work according to my own testing. I'm sure with some
  troubleshooting we could likely fix it, but that brings me to point #2:
* It was never actually enabled by default, and is still marked as
  experimental in the module parameter description
* If people were using it, someone probably would have probably seen a bug
  report about how it is currently not functional by now. That certainly
  doesn't appear to be the case, since before getting access to my own
  hardware I had to go out of my way to try finding someone to help test
  whether this legacy MST code even works - even amongst AMD employees.
* Getting rid of this code and only having atomic versions of the MST
  helpers to maintain is likely going to be a lot easier in the long run,
  and will make it a lot easier for others contributing to this code to
  follow along with what's happening.

FWIW - if anyone still wants this code to be in the tree and has a good
idea of how to support this without needing to maintain the legacy MST
helpers (trying to move them would probably be acceptable), I'm happy to
suggestions. But my hope is that we can just drop this code and forget
about it. I've already run this idea by Harry Wentland and Alex Deucher a
few times as well.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Wayne Lin <Wayne.Lin@amd.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Fangzhi Zuo <Jerry.Zuo@amd.com>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sean Paul <sean@poorly.run>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220817193847.557945-17-lyude@redhat.com

drivers/gpu/drm/radeon/Makefile

@@ -49,7 +49,7 @@ radeon-y += radeon_device.o radeon_asic.o radeon_kms.o \
 	rv770_smc.o cypress_dpm.o btc_dpm.o sumo_dpm.o sumo_smc.o trinity_dpm.o \
 	trinity_smc.o ni_dpm.o si_smc.o si_dpm.o kv_smc.o kv_dpm.o ci_smc.o \
 	ci_dpm.o dce6_afmt.o radeon_vm.o radeon_ucode.o radeon_ib.o \
-	radeon_sync.o radeon_audio.o radeon_dp_auxch.o radeon_dp_mst.o
+	radeon_sync.o radeon_audio.o radeon_dp_auxch.o
 
 radeon-$(CONFIG_MMU_NOTIFIER) += radeon_mn.o
 

drivers/gpu/drm/radeon/atombios_crtc.c

@@ -617,13 +617,6 @@ static u32 atombios_adjust_pll(struct drm_crtc *crtc,
 		}
 	}
 
-	if (radeon_encoder->is_mst_encoder) {
-		struct radeon_encoder_mst *mst_enc = radeon_encoder->enc_priv;
-		struct radeon_connector_atom_dig *dig_connector = mst_enc->connector->con_priv;
-
-		dp_clock = dig_connector->dp_clock;
-	}
-
 	/* use recommended ref_div for ss */
 	if (radeon_encoder->devices & (ATOM_DEVICE_LCD_SUPPORT)) {
 		if (radeon_crtc->ss_enabled) {
@@ -972,9 +965,7 @@ static bool atombios_crtc_prepare_pll(struct drm_crtc *crtc, struct drm_display_
 	radeon_crtc->bpc = 8;
 	radeon_crtc->ss_enabled = false;
 
-	if (radeon_encoder->is_mst_encoder) {
-		radeon_dp_mst_prepare_pll(crtc, mode);
-	} else if ((radeon_encoder->active_device & (ATOM_DEVICE_LCD_SUPPORT | ATOM_DEVICE_DFP_SUPPORT)) ||
+	if ((radeon_encoder->active_device & (ATOM_DEVICE_LCD_SUPPORT | ATOM_DEVICE_DFP_SUPPORT)) ||
 	    (radeon_encoder_get_dp_bridge_encoder_id(radeon_crtc->encoder) != ENCODER_OBJECT_ID_NONE)) {
 		struct radeon_encoder_atom_dig *dig = radeon_encoder->enc_priv;
 		struct drm_connector *connector =

drivers/gpu/drm/radeon/atombios_encoders.c

@@ -667,15 +667,7 @@ atombios_get_encoder_mode(struct drm_encoder *encoder)
 	struct drm_connector *connector;
 	struct radeon_connector *radeon_connector;
 	struct radeon_connector_atom_dig *dig_connector;
-	struct radeon_encoder_atom_dig *dig_enc;
 
-	if (radeon_encoder_is_digital(encoder)) {
-		dig_enc = radeon_encoder->enc_priv;
-		if (dig_enc->active_mst_links)
-			return ATOM_ENCODER_MODE_DP_MST;
-	}
-	if (radeon_encoder->is_mst_encoder || radeon_encoder->offset)
-		return ATOM_ENCODER_MODE_DP_MST;
 	/* dp bridges are always DP */
 	if (radeon_encoder_get_dp_bridge_encoder_id(encoder) != ENCODER_OBJECT_ID_NONE)
 		return ATOM_ENCODER_MODE_DP;
@@ -1723,10 +1715,6 @@ radeon_atom_encoder_dpms_dig(struct drm_encoder *encoder, int mode)
 	case DRM_MODE_DPMS_SUSPEND:
 	case DRM_MODE_DPMS_OFF:
 
-		/* don't power off encoders with active MST links */
-		if (dig->active_mst_links)
-			return;
-
 		if (ASIC_IS_DCE4(rdev)) {
 			if (ENCODER_MODE_IS_DP(atombios_get_encoder_mode(encoder)) && connector)
 				atombios_dig_encoder_setup(encoder, ATOM_ENCODER_CMD_DP_VIDEO_OFF, 0);
@@ -1992,53 +1980,6 @@ atombios_set_encoder_crtc_source(struct drm_encoder *encoder)
 	radeon_atombios_encoder_crtc_scratch_regs(encoder, radeon_crtc->crtc_id);
 }
 
-void
-atombios_set_mst_encoder_crtc_source(struct drm_encoder *encoder, int fe)
-{
-	struct drm_device *dev = encoder->dev;
-	struct radeon_device *rdev = dev->dev_private;
-	struct radeon_crtc *radeon_crtc = to_radeon_crtc(encoder->crtc);
-	int index = GetIndexIntoMasterTable(COMMAND, SelectCRTC_Source);
-	uint8_t frev, crev;
-	union crtc_source_param args;
-
-	memset(&args, 0, sizeof(args));
-
-	if (!atom_parse_cmd_header(rdev->mode_info.atom_context, index, &frev, &crev))
-		return;
-
-	if (frev != 1 && crev != 2)
-		DRM_ERROR("Unknown table for MST %d, %d\n", frev, crev);
-
-	args.v2.ucCRTC = radeon_crtc->crtc_id;
-	args.v2.ucEncodeMode = ATOM_ENCODER_MODE_DP_MST;
-
-	switch (fe) {
-	case 0:
-		args.v2.ucEncoderID = ASIC_INT_DIG1_ENCODER_ID;
-		break;
-	case 1:
-		args.v2.ucEncoderID = ASIC_INT_DIG2_ENCODER_ID;
-		break;
-	case 2:
-		args.v2.ucEncoderID = ASIC_INT_DIG3_ENCODER_ID;
-		break;
-	case 3:
-		args.v2.ucEncoderID = ASIC_INT_DIG4_ENCODER_ID;
-		break;
-	case 4:
-		args.v2.ucEncoderID = ASIC_INT_DIG5_ENCODER_ID;
-		break;
-	case 5:
-		args.v2.ucEncoderID = ASIC_INT_DIG6_ENCODER_ID;
-		break;
-	case 6:
-		args.v2.ucEncoderID = ASIC_INT_DIG7_ENCODER_ID;
-		break;
-	}
-	atom_execute_table(rdev->mode_info.atom_context, index, (uint32_t *)&args);
-}
-
 static void
 atombios_apply_encoder_quirks(struct drm_encoder *encoder,
 			      struct drm_display_mode *mode)

drivers/gpu/drm/radeon/radeon_atombios.c

@@ -826,8 +826,6 @@ bool radeon_get_atom_connector_info_from_object_table(struct drm_device *dev)
 	}
 
 	radeon_link_encoder_connector(dev);
-
-	radeon_setup_mst_connector(dev);
 	return true;
 }
 

drivers/gpu/drm/radeon/radeon_connectors.c

@@ -37,33 +37,12 @@
 #include <linux/pm_runtime.h>
 #include <linux/vga_switcheroo.h>
 
-static int radeon_dp_handle_hpd(struct drm_connector *connector)
-{
-	struct radeon_connector *radeon_connector = to_radeon_connector(connector);
-	int ret;
-
-	ret = radeon_dp_mst_check_status(radeon_connector);
-	if (ret == -EINVAL)
-		return 1;
-	return 0;
-}
 void radeon_connector_hotplug(struct drm_connector *connector)
 {
 	struct drm_device *dev = connector->dev;
 	struct radeon_device *rdev = dev->dev_private;
 	struct radeon_connector *radeon_connector = to_radeon_connector(connector);
 
-	if (connector->connector_type == DRM_MODE_CONNECTOR_DisplayPort) {
-		struct radeon_connector_atom_dig *dig_connector =
-			radeon_connector->con_priv;
-
-		if (radeon_connector->is_mst_connector)
-			return;
-		if (dig_connector->is_mst) {
-			radeon_dp_handle_hpd(connector);
-			return;
-		}
-	}
 	/* bail if the connector does not have hpd pin, e.g.,
 	 * VGA, TV, etc.
 	 */
@@ -1664,9 +1643,6 @@ radeon_dp_detect(struct drm_connector *connector, bool force)
 	struct drm_encoder *encoder = radeon_best_single_encoder(connector);
 	int r;
 
-	if (radeon_dig_connector->is_mst)
-		return connector_status_disconnected;
-
 	if (!drm_kms_helper_is_poll_worker()) {
 		r = pm_runtime_get_sync(connector->dev->dev);
 		if (r < 0) {
@@ -1729,21 +1705,12 @@ radeon_dp_detect(struct drm_connector *connector, bool force)
 		radeon_dig_connector->dp_sink_type = radeon_dp_getsinktype(radeon_connector);
 		if (radeon_hpd_sense(rdev, radeon_connector->hpd.hpd)) {
 			ret = connector_status_connected;
-			if (radeon_dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT) {
+			if (radeon_dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT)
 				radeon_dp_getdpcd(radeon_connector);
-				r = radeon_dp_mst_probe(radeon_connector);
-				if (r == 1)
-					ret = connector_status_disconnected;
-			}
 		} else {
 			if (radeon_dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT) {
-				if (radeon_dp_getdpcd(radeon_connector)) {
-					r = radeon_dp_mst_probe(radeon_connector);
-					if (r == 1)
-						ret = connector_status_disconnected;
-					else
-						ret = connector_status_connected;
-				}
+				if (radeon_dp_getdpcd(radeon_connector))
+					ret = connector_status_connected;
 			} else {
 				/* try non-aux ddc (DP to DVI/HDMI/etc. adapter) */
 				if (radeon_ddc_probe(radeon_connector, false))
@@ -2561,25 +2528,3 @@ radeon_add_legacy_connector(struct drm_device *dev,
 	connector->display_info.subpixel_order = subpixel_order;
 	drm_connector_register(connector);
 }
-
-void radeon_setup_mst_connector(struct drm_device *dev)
-{
-	struct radeon_device *rdev = dev->dev_private;
-	struct drm_connector *connector;
-	struct radeon_connector *radeon_connector;
-
-	if (!ASIC_IS_DCE5(rdev))
-		return;
-
-	if (radeon_mst == 0)
-		return;
-
-	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
-		radeon_connector = to_radeon_connector(connector);
-
-		if (connector->connector_type != DRM_MODE_CONNECTOR_DisplayPort)
-			continue;
-
-		radeon_dp_mst_init(radeon_connector);
-	}
-}

drivers/gpu/drm/radeon/radeon_device.c

@@ -1438,7 +1438,6 @@ int radeon_device_init(struct radeon_device *rdev,
 		goto failed;
 
 	radeon_gem_debugfs_init(rdev);
-	radeon_mst_debugfs_init(rdev);
 
 	if (rdev->flags & RADEON_IS_AGP && !rdev->accel_working) {
 		/* Acceleration not working on AGP card try again

drivers/gpu/drm/radeon/radeon_drv.c

@@ -172,7 +172,6 @@ int radeon_use_pflipirq = 2;
 int radeon_bapm = -1;
 int radeon_backlight = -1;
 int radeon_auxch = -1;
-int radeon_mst = 0;
 int radeon_uvd = 1;
 int radeon_vce = 1;
 
@@ -263,9 +262,6 @@ module_param_named(backlight, radeon_backlight, int, 0444);
 MODULE_PARM_DESC(auxch, "Use native auxch experimental support (1 = enable, 0 = disable, -1 = auto)");
 module_param_named(auxch, radeon_auxch, int, 0444);
 
-MODULE_PARM_DESC(mst, "DisplayPort MST experimental support (1 = enable, 0 = disable)");
-module_param_named(mst, radeon_mst, int, 0444);
-
 MODULE_PARM_DESC(uvd, "uvd enable/disable uvd support (1 = enable, 0 = disable)");
 module_param_named(uvd, radeon_uvd, int, 0444);
 

drivers/gpu/drm/radeon/radeon_encoders.c

@@ -244,16 +244,7 @@ radeon_get_connector_for_encoder(struct drm_encoder *encoder)
 
 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 		radeon_connector = to_radeon_connector(connector);
-		if (radeon_encoder->is_mst_encoder) {
-			struct radeon_encoder_mst *mst_enc;
-
-			if (!radeon_connector->is_mst_connector)
-				continue;
-
-			mst_enc = radeon_encoder->enc_priv;
-			if (mst_enc->connector == radeon_connector->mst_port)
-				return connector;
-		} else if (radeon_encoder->active_device & radeon_connector->devices)
+		if (radeon_encoder->active_device & radeon_connector->devices)
 			return connector;
 	}
 	return NULL;
@@ -399,9 +390,6 @@ bool radeon_dig_monitor_is_duallink(struct drm_encoder *encoder,
 	case DRM_MODE_CONNECTOR_DVID:
 	case DRM_MODE_CONNECTOR_HDMIA:
 	case DRM_MODE_CONNECTOR_DisplayPort:
-		if (radeon_connector->is_mst_connector)
-			return false;
-
 		dig_connector = radeon_connector->con_priv;
 		if ((dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_DISPLAYPORT) ||
 		    (dig_connector->dp_sink_type == CONNECTOR_OBJECT_ID_eDP))

drivers/gpu/drm/radeon/radeon_irq_kms.c

@@ -100,16 +100,8 @@ static void radeon_hotplug_work_func(struct work_struct *work)
 
 static void radeon_dp_work_func(struct work_struct *work)
 {
-	struct radeon_device *rdev = container_of(work, struct radeon_device,
-						  dp_work);
-	struct drm_device *dev = rdev->ddev;
-	struct drm_mode_config *mode_config = &dev->mode_config;
-	struct drm_connector *connector;
-
-	/* this should take a mutex */
-	list_for_each_entry(connector, &mode_config->connector_list, head)
-		radeon_connector_hotplug(connector);
 }
+
 /**
  * radeon_driver_irq_preinstall_kms - drm irq preinstall callback
  *

drivers/gpu/drm/radeon/radeon_mode.h

@@ -31,7 +31,6 @@
 #define RADEON_MODE_H
 
 #include <drm/display/drm_dp_helper.h>
-#include <drm/display/drm_dp_mst_helper.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_edid.h>
 #include <drm/drm_encoder.h>
@@ -436,24 +435,12 @@ struct radeon_encoder_atom_dig {
 	int panel_mode;
 	struct radeon_afmt *afmt;
 	struct r600_audio_pin *pin;
-	int active_mst_links;
 };
 
 struct radeon_encoder_atom_dac {
 	enum radeon_tv_std tv_std;
 };
 
-struct radeon_encoder_mst {
-	int crtc;
-	struct radeon_encoder *primary;
-	struct radeon_connector *connector;
-	struct drm_dp_mst_port *port;
-	int pbn;
-	int fe;
-	bool fe_from_be;
-	bool enc_active;
-};
-
 struct radeon_encoder {
 	struct drm_encoder base;
 	uint32_t encoder_enum;
@@ -475,8 +462,6 @@ struct radeon_encoder {
 	enum radeon_output_csc output_csc;
 	bool can_mst;
 	uint32_t offset;
-	bool is_mst_encoder;
-	/* front end for this mst encoder */
 };
 
 struct radeon_connector_atom_dig {
@@ -487,7 +472,6 @@ struct radeon_connector_atom_dig {
 	int dp_clock;
 	int dp_lane_count;
 	bool edp_on;
-	bool is_mst;
 };
 
 struct radeon_gpio_rec {
@@ -531,11 +515,6 @@ enum radeon_connector_dither {
 	RADEON_FMT_DITHER_ENABLE = 1,
 };
 
-struct stream_attribs {
-	uint16_t fe;
-	uint16_t slots;
-};
-
 struct radeon_connector {
 	struct drm_connector base;
 	uint32_t connector_id;
@@ -558,14 +537,6 @@ struct radeon_connector {
 	enum radeon_connector_audio audio;
 	enum radeon_connector_dither dither;
 	int pixelclock_for_modeset;
-	bool is_mst_connector;
-	struct radeon_connector *mst_port;
-	struct drm_dp_mst_port *port;
-	struct drm_dp_mst_topology_mgr mst_mgr;
-
-	struct radeon_encoder *mst_encoder;
-	struct stream_attribs cur_stream_attribs[6];
-	int enabled_attribs;
 };
 
 #define ENCODER_MODE_IS_DP(em) (((em) == ATOM_ENCODER_MODE_DP) || \
@@ -767,8 +738,6 @@ extern void atombios_dig_transmitter_setup(struct drm_encoder *encoder,
 extern void atombios_dig_transmitter_setup2(struct drm_encoder *encoder,
 					    int action, uint8_t lane_num,
 					    uint8_t lane_set, int fe);
-extern void atombios_set_mst_encoder_crtc_source(struct drm_encoder *encoder,
-						 int fe);
 extern void radeon_atom_ext_encoder_setup_ddc(struct drm_encoder *encoder);
 extern struct drm_encoder *radeon_get_external_encoder(struct drm_encoder *encoder);
 void radeon_atom_copy_swap(u8 *dst, u8 *src, u8 num_bytes, bool to_le);
@@ -986,15 +955,6 @@ void radeon_crtc_handle_flip(struct radeon_device *rdev, int crtc_id);
 
 int radeon_align_pitch(struct radeon_device *rdev, int width, int bpp, bool tiled);
 
-/* mst */
-int radeon_dp_mst_init(struct radeon_connector *radeon_connector);
-int radeon_dp_mst_probe(struct radeon_connector *radeon_connector);
-int radeon_dp_mst_check_status(struct radeon_connector *radeon_connector);
-void radeon_mst_debugfs_init(struct radeon_device *rdev);
-void radeon_dp_mst_prepare_pll(struct drm_crtc *crtc, struct drm_display_mode *mode);
-
-void radeon_setup_mst_connector(struct drm_device *dev);
-
 int radeon_atom_pick_dig_encoder(struct drm_encoder *encoder, int fe_idx);
 void radeon_atom_release_dig_encoder(struct radeon_device *rdev, int enc_idx);
 #endif